KR20010032233A - Pulsed corona discharge apparatus with radial design - Google Patents

Abstract

The present invention relates to a device for regulating contaminated fluid material such as gas using pulsed corona discharge. The apparatus comprises a reactor section 10 and a power supply section 12. This reactor section 10 is arranged centrally around each first electrode 16 with a plurality of first electrodes 16 electrically interconnected to the header plate 14 and electrically connected to the reactor plate 20. It has a plurality of second electrodes 22 interconnected with each other. Positioning the inner electrode 102 in the outer electrode 120 increases the exposed overlapping surface area of the electrode. Increasing the surface area of the electrodes increases the operating life of the device proportionally.

Description

Pulsed corona discharge apparatus with radial design

Flowable materials, which are generally gases but also contain liquids, are often contaminated with harmful or aromatic materials, such as volatile organic compounds. Prior to releasing this fluid substance to the atmosphere, it is desirable to adjust or remove this harmful compound and be forced by law. Methods of adjusting harmful compounds suspended in flowable materials include hot thermal incineration, catalytic incineration, and absorption using materials such as activated carbon. Such methods tend to be expensive and have low throughput.

Another approach is to react these harmful compounds with the flow of high-energy electrons created by the partial electrolysis of the flowable material to decompose the harmful material into harmless materials such as water and carbon dioxide. Such a method is described in US Pat. No. 5,236,672 to Nunez et al. And US Pat. No. 5,490,973 to Grothaus et al.

Gross et al. Patent describe a reactor having a wire electrode extending along the longitudinal axis of the tubular electrode surrounding the wire electrode. Insulators at the inlet and outlet of the tubular electrode centered on the wire electrode along the axis of the tubular electrode provide tension to prevent the wire electrode from sagging and electrically insulate the wire electrode from the tubular electrode. This insulator is partitioned to allow entry of the flowable material and gas is introduced into each reactor tube individually. As a result, complicated gas sealing is required, which results in a low throughput and a large number of required mechanical parts.

In addition, the patent of Grosse et al. Describes a method of controlling a high voltage power supply, which does not sense and thus fails to adjust the noxious gas, which can destroy the reactor itself.

The operation of the spark gap switch causes corrosion of the switch electrode, so that the length of the gap becomes large. Corrosion of an electrode is a function of the current through this electrode and the time that this current flows through the electrode. Certain switches are typically set to have a corrosion rate measured in micrograms per coulombic of the total charge delivered through the switch electrode (total load transfer is the time-based amount of the absolute value of the current through the switch). . Typical switch corrosion values range from 100 to 200 micrograms per coulomb. In certain circuits, the breakdown voltage of the switch is generally set by adjusting the pressure (density) of the switch gas dielectric (eg, air or sulfur hexafluoride SF ₆ ).

Once the electrode corrodes and the gap extends to some extent, it is no longer possible to change the switch gas density to adjust its decomposition voltage to a predetermined value. At this point, the switch no longer works.

In the design of a conventional axial spark switch, the insulating material is crushed by the spark, which tends to contaminate the insulating material, reducing the operating life of the switch.

U.S. Patent 5,502,346 (Hsieh) describes an electrochemical generator, for example for producing ozone.

U.S. Patent 4,126,808 (Rich) describes a high voltage two stage triggered vacuum gap with high voltage terminals at both ends of the shell.

U. S. Patent 3,996, 438 (Kurtz) describes a vacuum circuit interrupter having two types of rod electrodes in which a plurality of first electrodes are inserted between the plurality of second electrodes.

U. S. Patent 3,854, 068 (Rich) describes a shielding structure for a vacuum arc emitter.

As can be seen in the state of the art, there is a need for switches that can be operated continuously and repeatedly, particularly at voltages in excess of 1 kV where the switch operating life exceeds the total charge transfer of 1 million coulombs.

There is also a need for a pulsed corona discharger that modulates contaminated fluid material that does not have the disadvantages of the prior art discussed above.

The present invention relates to a pulsed corona discharge device for adjusting contaminated fluid material. More specifically, this flowable material passes through a reactor vessel having a plurality of electrically interconnected wire electrodes each bounded by a second electrode. The high voltage pulses to this wire electrode produce a corona discharge that emits light. The radial design of the present invention overlaps the inner electrode in the outer electrode to increase its exposed electrode surface area.

1 is a longitudinal sectional view showing a reactor portion of a system of the present invention.

2 is a cross sectional view showing a header portion of the present invention;

3 is a cross-sectional side view illustrating a plurality of second electrodes surrounding the first electrode in accordance with the present invention.

4 is a longitudinal sectional view showing a power supply portion of the system of the present invention.

Figure 5 is a side sectional view of a commercial axial spark gap switch known in the art.

Figure 6 is a side sectional view of a spark gap switch constructed in accordance with the present invention.

7 illustrates an embodiment of a switch with an extended electrode.

8 is a sectional view seen from above of the spark switch.

9 illustrates an embodiment of an electrode that is stacked in multiple layers.

10 is an illustration of a coaxial spark switch.

11 illustrates an example coaxial spark switch connected to a power source and an electrical load.

Accordingly, it is an object of the present invention to provide a reactor for regulating flowable material contaminated with pulsed corona discharges. One of the features of the present invention is a single common header plate electrically interconnected to a plurality of first electrodes and an electrical interconnection to a plurality of second electrodes disposed concentrically around each first electrode. There is a common reactor plate connected. Another feature of the present invention is that the second electrode provides a plurality of channels for receiving tubular and contaminated fluid. A single inlet effectively communicates the contaminated fluid to all tubular electrodes and a single inlet effectively removes the adjusted fluid. Another feature of the invention is that an intermittent high voltage pulse is applied to the header plate by the power supply and distributed to the plurality of first electrodes.

One of the advantages of the present invention is that the reactor has a simplified design requiring only a limited number of mechanical parts. Another advantage is that the power supply is easily separated from the reactor for easy part exchange and cleaning of the reactor. Another advantage of the present invention is that the power supply is controlled in a manner that detects and corrects inappropriate high voltage discharges. Another advantage of the present invention is that the pulsed corona discharge effectively regulates the contaminated fluent material.

According to the present invention, a system for treating contaminated flow is provided. The system includes a power supply capable of providing intermittent high voltage pulses to an electrically conductive header plate. The plurality of first electrodes are electrically connected to the header plate. A plurality of second electrodes, each concentrically arranged around one of the first electrodes, define a plurality of channels to contain the contaminated fluid. The electrically grounded reactor plate is electrically connected to each of the plurality of second electrodes and electrically insulated from both the header plate and the plurality of first electrodes. The inlet introduces contaminated flow into each channel and the outlet recovers the adjusted flow.

The present invention increases the operating area of the spark switch by increasing the amount of exposed area of the electrode.

A second embodiment of the invention is directed to a spark switch having a first end plate and a second end plate. This switch has an inner electrode having an outer wall and an outer electrode. Both inner and outer electrodes are disposed on and bonded to the first and second end plates. The outer electrode defines a cavity for receiving a portion of the inner electrode. The outer wall of the inner electrode and the cavity of the outer electrode form a radial gap.

An insulating material is disposed in the sleeve shape around the external electrode. This insulation is protected from exposure to contaminants during conversion because the external electrode acts as a barrier to convert the byproduct.

The third embodiment is directed to a coaxial switch having an electrode connected to an electrical connector. Insulation is provided at both ends of the coaxial switch and means are provided for maintaining the position of the insulation. This embodiment has a conductive tube connected to the power source and an electrical load that provides a path for returning current from the load to the power source.

The fourth embodiment is for a third electrode which overlaps within the inner electrode to form another radial gap.

The fifth embodiment is directed to a switch having suction and discharge ports, where accumulated debris can be removed.

The above objects, features and advantages are more apparent from the following specification and drawings.

The system for treating contaminated fluid according to the present invention comprises two sections, a reactor section 10 for treating contaminated fluid and a power supply section 12 providing an intermittent high voltage pulse current to the reactor section. Has The reactor section 10 is shown in FIG. 1. A portion of the power supply section 12 is shown in FIG. The entirety of this power supply section 12 is shown in FIG.

1 illustrates the reactor section 10 in cross section. This reactor section 10 preferably comprises an electrically conductive header plate 14 formed of an electrically conductive metal such as stainless steel.

A plurality of first electrodes 16 are electrically interconnected to this header plate 14. This electrical interconnection can be made by any means that effectively supports the first electrode 16 in a tensioned state, including bolting, welding, soldering and brazing. Since a high voltage is transmitted from the header plate 14 to the first electrode 16 via this electrical interconnection, means having an electrically low resistance is preferred. The best attachment means is bolt fastening, which has the additional advantage that the first electrode 16 can be easily replaced.

This first electrode 16 may be of any shape desired and may be formed of any suitable electrically conductive material. Preferred materials for the first electrode include stainless steel. The preferred shape of this first electrode is a wire having a generally circular cross section with a diameter of about 0.001 inch (0.003 cm) to 0.1 inch (0.254 cm). More preferably, the diameter of this first electrode is from about 0.01 inch to about 0.05 inch (0.025-0.127 cm).

FIG. 2 is a cross sectional view of the reactor system illustrated in FIG. 1 seen from section line 2-2. FIG. 2 shows that the first electrode 16 is disposed around the header plate 14. Preferably, the plurality of first electrodes 16 are symmetrically directed about the longitudinal axis 18 of the reactor section. 2 illustrates eight first electrodes, however, any number of modifications can be used in the individual reactor designs. The system is preferably considered to comprise 1 to 20 first electrodes.

Referring again to FIG. 1, an electrically conductive reactor plate 20 is spaced apart from and electrically insulated from the header plate 14. This reactor plate 20 is formed of an electrically conductive metal, preferably stainless steel. This plate plate has sufficient strength to support the plurality of second electrodes 22. Generally, the reactor plate has a thickness of about 0.125 inches to about 1.5 inches (0.318-3.81 cm) and more preferably about 0.5 inches to about 1 inch (1.27-2.54 cm).

Between the header plate 14 and the reactor plate 20 is electrically insulated by a flowable material around the periphery of the header plate 14 and in a first opening 24 extending through the reactor plate 20. The first opening 24 facilitates the entry of the first electrode 16 into the bore of the tubular second electrode 22. Preferably, the second electrode 22 is arranged concentrically around the first electrode 16.

The high voltage pulse applied to the header plate 14 is electrically discharged between the first electrode 16 and the second electrode 22, which is entirely contained in the volume of the tubular electrode 22. In order to ensure that this discharge takes place only in the volume surrounded by the second electrode 22, the minimum distance 26 between the first electrode 16 and the reactor plate 20 is at least equal to the first electrode 16. It should be equal to the distance between the second electrodes 22. In addition, the first opening 24 should have a shape such that the electric field in the region of the first opening 24 does not exceed the electric field generated between the first electrode 16 and the second electrode 22.

Electrical insulation is further provided between the header plate 14 and the reactor plate 20 by the concentrically disposed dielectric material 28. This dielectric material 28 is bonded to both the reactor plate 20 and the header plate 14 and keeps these two elements at a fixed distance away from each other. This dielectric 28 may be any suitable electrically nonconductive material having a breakdown voltage greater than the voltage applied by the power supply section 12. Suitable materials for the dielectric 28 include ceramics and polymers. The polymer is good because the adhesion of the dielectric 28 to both the reactor plate 20 and the header plate 14 is preferably accomplished by mechanical means such as using screws, and the machinability of the polymer is also advantageous. Preferred polymers include polytetrafluoroethylene (TEFLON), a trademark of DuPont, Wilmington, Delaware.

As shown in FIG. 2, the dielectric 28 is centered relative to the first electrode 16 so that the first electrode 16 is not disturbed by the dielectric 28. The diameter of the dielectric 28 should be large enough to prevent a change in tension between each first electrode 16 due to changing the header plate 14 in a direction that is not parallel to the reactor plate 20. Preferably, the diameter of the dielectric 28 is at least 40% of the diameter of the header plate 14. For example, if the header plate 14 is a circle having a diameter of 6.25 inches (15.9 cm), the dielectric has a diameter of about 2.50 inches (6.4 cm).

The diameter of the dielectric 28 is effective to prevent the occurrence of an electric arc between the header plate 14 and the reactor plate 20, and referring again to FIG. 1, the distance 30 is between about 0.25 and about 2 inches (0.64). -5.08 cm) and more preferably about 1 inch to about 2 inches (2.54-5.08 cm).

In addition, the dielectric 28 acts to position the header plate 14 at a fixed distance from the reactor plate 20 such that each first electrode is positioned concentrically with respect to the second electrode. To pass.

Pulsed corona discharge is formed to spread between the first electrode 16 and the second electrode 22. The potential difference electrically required to cause a discharge between the first electrode 16 and the second electrode 22 raises the first electrode 16 to a sufficiently high voltage to form a discharge, and the reactor plate 20 and the ground potential ( 32, having a second electrode 22 electrically interconnected to ground potential. This high voltage can be positive or negative for a grounded element.

The gas manifold 36 is connected to the reactor plate 20 and surrounds the reactor plate 20 and the header plate 14 to form a gas receiving cavity 34. The gas manifold 36 is hermetically sealed by a flange 38 that couples to the reactor plate 20 by bolting, welding, brazing, or the like. Preferably, a compliant O ring (not shown) may be disposed between this flange 38 and the reactor plate 20. When the contaminated fluid 40 is delivered to the gas receiving cavity 34 through the inlet 42, this contaminated fluid 40 fills the gas receiving chamber 34 and is driven by the second electrode 20. It flows down into a number of channels 44 that are formed. The combination of the reactor plate 20 and the gas manifold 36 including the first opening 24 allows the contaminated fluid 40 to flow from the inlet to the combination of the second electrode 22 and the first electrode 16. Effectively to each reaction chamber defined by It is not necessary to provide separate gas inlets to each reaction chamber and no separate baffling into each channel 44 is required.

Gas manifold 36 may be formed of any suitable material. To minimize the risk of electrical shock, gas manifold 36 is preferably formed of an electrically conductive material, such as stainless steel.

The second electrode 22 is electrically interconnected to the reactor plate 20 and extends away from the header plate 14 for an extended distance. The length of the second electrode 22 defines the length of the reactor chamber and the time for which the contaminated fluid is in contact with and adjusted to the corona discharge. Generally, the length 44 of the second electrode 22 is about 6 inches to about 60 inches (15.24-152.4 cm).

The second electrode is generally tubular with an inner diameter 46 of about 0.5 to about 3 inches (1.27-7.62 cm).

3 shows a cross section of the reactor section 10 taken along cut line 3-3 and includes a plurality of reactors comprising a combination of a second electrode 22 and a first electrode 16 extending within the reactor housing 48. Illustrate the chamber. The volume of reactor chambers effective for adjusting contaminated flow is the number of reactor chambers multiplied by the cross-sectional area of each chamber and the length of each chamber. For a reactor with eight reactor chambers, each 36 inches (91.44 cm) long and 1 inch (2.54 cm) internal diameter, the total effective volume is 226 in ³ (3074.8 cm ³ ).

The second electrode 22 is formed of a suitable electrically conductive material that resists heating due to pulsed corona discharge and erosion and deformation due to contact with an electric arc. One material suitable for the second electrode 22 is stainless steel. Suitable wall thickness for the second electrode is about 0.05 to 0.2 in (0.127-0.508 cm).

Referring again to FIG. 1, the second electrode 22 terminates in the downstream reactor plate 50, which is preferably formed of an electrically conductive material, and is more preferably formed of the same material as the reactor plate 20. The second opening 52 extends through the downstream reactor plate 50 and withdraws the adjusted flow 54 from the reaction chamber. This second opening 50 preferably has a size and shape similar to the first opening.

The regulated fluid 54 may be discharged directly to the atmosphere, or preferably contained within the gas exhaust cavity 56 in which the sensor 58 determines the level of volatile organic compounds or other harmful substances. If the content of this harmful substance is low enough, the adjusted fluid 54 is discharged through the outlet 60. If the content of the harmful substance is too high, the reactor 160 is partially closed to lower the flow rate of the flowing material through the reactor, thereby increasing the adjustment level.

Alternatively and preferably, the sensor 58 is controlled with a power supply control unit 79 (FIG. 4) and a feedback loop so that the power delivered to the reactor is automatically adjusted in response to variations in exhaust flow pollutant concentrations. As the concentration increases, the sensor 58 causes the power supply control unit to increase the power to the reactor. Then, when the exhaust concentration is stabilized to a predetermined value and a program is input to the power supply control unit to the operator, the sensor 58 causes the control unit to reduce the power to the reactor. The power delivered to this reactor can be controlled by adjusting the voltage delivered to the header plate, or preferably by adjusting the pulse repetition rate. The power delivered to this reactor is approximately proportional to the voltage squared with the repetition rate. Automatic feedback and control of these emission concentrations has the advantage of ensuring efficient operation of the system over a period of varying intake contaminant concentrations.

The gas discharge cavity 56 is downstream with an end cap 62 which is hermetically sealed to the downstream reactor plate 50 and provides sufficient space for the gas discharge cavity 56 and the tension plate 64. Bounded by the side reactor plate 50. Preferably, the end cap 62 is formed of an electrically nonconductive material that prevents accidental contact with an electrode that may have a high voltage potential difference. The end cap 62 may also be formed of a conductive material that provides shielding of high voltage elements.

The tension plate 64 supports the first electrode 16 and cooperates with the header plate 14 to keep the first electrode under tension and to be approximately parallel to the longitudinal axis 18 and each second electrode ( 22) to be centered within. Preferably, tension plate 64 is formed of an electrically conductive material, such as a stainless material.

This tension plate 64 is made of a dielectric similar to that of the dielectric 28 or bonded to the end cap 62 by a polymer adhesive 66 as illustrated in FIG. 1, or a machine such as a bolt or screw. It can be supported by the downstream reactor plate 50 using any suitable means.

An opening in the gas manifold 36 houses the interconnect portion 68 of the power supply portion 12. The interface 70 between the power supply section 12 and the reactor section 10 is hermetic sealed by inserting an O-ring, a gasket or other suitable means. Preferably, the power supply section 12 is permanently attached to the manifold 36 such that the power supply section can be separated from the reactor section 10 at the interface of the flange 38 and the reactor plate 20. Facilitate the exchange of parts and elements.

Alternatively, the interface 70 allows the interconnect portion 68 to easily remove the power supply section 12 from the reactor section 10. The power supply electrode 72 is centrally disposed within the interconnect portion 68. This powered electrode may be any electrically conductive material, such as copper alloy or stainless steel. The interconnect portion 68 is electrically insulator.

The front portion 74 of the power supply electrode 72 applies a compressive force upon detachable contact, such as a leaf spring or a compression spring 76. The compression spring 76 is formed of an electrically conductive material, such as stainless steel, and also provides low resistance electrical contact between the power supply electrode 72 of the power supply section 12 and the header plate 14. In contact with the header plate 14. Since this compression spring 76 is not mechanically or chemically bonded to the header plate 14, separation from the reactor section of this power supply section is easy and the alignment of the two is not a big problem. As best illustrated in FIG. 2, the compression spring 76 generally contacts the centrally disposed portion of the header plate 14 to provide electrical energy to each first electrode 16.

The power supply portion 12 is illustrated in cross section in FIG. 4. An alternating current (AC) power source 78, such as an intermittent 120 volts, 60 cycles per second, transfers alternating current to a power supply 80 that converts low voltage (AC) to high voltage direct current (DC).

This DC power supply 80 converts the alternating current from the AC power supply 78 into a direct current output voltage 84 exceeding 20 kV, preferably between about 30 kV and 40 kV. This output voltage 84 is conducted to an isolation resistor 86 connected in series with the DC power supply 80. This insulation resistor has a resistance of at least 20 kΩ and is preferably about 100 kΩ. This insulation resistor isolates the power supply 78 from the high speed switch 88.

Output current 89 is conducted from isolation resistor 86 to capacitor 90 and then grounded. This capacitor 90 stores at least 0.05 Joules of electrical energy, preferably about 1 joule. The fast switch 88 then breaks the connection of the capacitor 90 to the header plate 20 (FIG. 1) via a power supply electrode 72 that conducts a voltage pulse between about 10 kV and 200 kV. .

The voltage of this capacitor 90 energizes the first electrode 92 of the spark gap switch 88. When the charged voltage applied to the first electrode 92 exceeds the decomposition voltage of the gap 94 included in the spark gap switch 88, the arc causes the first electrode 92 and the power supply electrode 72. To connect the spark gap second electrode 96 that excites each other.

The spark gap 94 may be filled with any suitable gas, including air. Hydrogen is good because the voltage recovery characteristic of hydrogen allows a high pulse repetition rate.

The high speed switch is a voltage pulse having a magnitude of about 5 nanoseconds (5 sec ^-9 ) to 1 microsecond (1 sec ^-6 ) in the interval between pulses ranging from about 100 microseconds (100 sec ^-6 ) to 1 second. To pass.

When discharge occurs in the output circuit of the DC power supply, there is a feedback loop 99 between the DC power supply 80 and the control unit 79. This discharge may be a predetermined discharge in reactor section 10 or may be an unwanted discharge anywhere in the high voltage circuit. Upon receiving a signal from this feedback loop 99, the control unit 79 prevents the capacitor 90 from being further charged by the DC power supply 80. When the interval between the predetermined pulses has elapsed, this control unit 79 causes the DC power supply to start charging the capacitor 90 for another cycle.

Synchronization by the feedback loop 99 is preferred because the DC power supply 80 is completely insulated from the capacitor 90 immediately after the fast switch 88 is closed. Otherwise, this DC power supply will transfer energy directly to the reactor section 10 in an inefficient manner.

Referring again to FIG. 1, when the power supply electrode 72 applies a voltage pulse to the header plate 14, each first electrode is of the same potential difference. When this potential difference exceeds the decomposition voltage of the flowable material, the flow of electrons 100 flows between the first electrode 16 and the second electrode 22 in the form of a high energy corona. When the contaminated fluid 44 passes through the excited electrons 100, the collision between the flowable material and the electrons creates a highly reactive species called radicals. This radical eventually reacts with the pollutant species to break it down into more harmless substances such as O ₂ , N ₂ , CO ₂ and H ₂ O.

Referring again to FIG. 4, when voltage is applied to the first electrode for an excessively long time, the processing efficiency decreases due to the acceleration of the ion species in the fluid gas. This results in thermal arcs with reduced energy inefficiency, reduced processing volume and electrode damage. Therefore, the high voltage pulse is kept short by the special design of the power supply section 12.

Although this powering section 12 has been described in conjunction with the reaction section 10 of the pulsed corona discharger of the present invention, this powering section can be used in any application that requires a short duration high voltage current pulse.

Spark gap switches are the most rugged switches available for high peak power systems. However, they are generally limited to less than the operating life of 500,000 coulombs, where one coulomb is a charge carried by a current of 1 ampere per second.

The operation of the spark gap switch creates a spark breakdown current between the electrodes. Decomposition spark currents are currents between electrodes that produce hot plasma with by-product debris in the gaseous, molten and solid state. Decomposition spark currents are harmful to the surface of the electrodes, causing them to puncture and corrode. In addition, debris from the decomposition spark current degrades other peripheral materials, such as the insulation used to hold the electrodes in place.

The present invention also discloses a novel and improved spark switch design that inserts an inner electrode into an outer electrode, thereby increasing the operating life of the switch. This design allows the external electrode to act as a containment vessel, limiting the trajectory of the debris due to decomposition currents.

5 shows an axial spark switch 201 of the prior art. The exposed electrode surface area is limited to the exposure of the upper electrode plate 180 to the lower electrode plate 190.

The design of these two electrode plates 180, 190 generally exposes the insulating material 130, which is acrylic, ceramic or other insulating material surrounding the electrode plates 180. 190, to spark debris from spark decomposition. The gap 210 between the electrode plates 180, 190 is air or another suitable gas, such as sulfur hexafluoride (SF ₆ ) or carbon dioxide (CO ₂ ).

As illustrated in FIGS. 6 and 7, in the spark switch of the present invention, the surface area of the exposed electrode is significantly increased with the inner electrode 102 surrounded by or overlapping the outer electrode 120. This overlapping setting allows the exposed electrode surface area of the inner electrode 102 and the outer electrode 120 to be up to about five times the exposed electrode surface area of a conventional axial spark switch of the same total volume.

The spark switch of the present invention allows scaling to a wide electrode area at a constant switch diameter without increasing the action on the tie rod 150. In order to increase the electrode area of a conventional axial switch, it is necessary to increase the switch diameter, which exerts a higher stress on the tie rod 150.

6 and 7 respectively show a spark switch having end terminals 110 and 111 connected to conductors 115 and 116 at the first end plate 140 and the second end plate 162 of the switch, respectively. Shows. These conductors 115 and 116 allow the switch to be connected to an electrical power source (not shown) and an electrical load (not shown). This end plate is made of steel, aluminum, or other rigid conductive material. The first end plate 140 is connected to the second end plate via a plurality of tie rods 150 extending longitudinally between the first end plate 140 and the second end plate 162 of the switch 101. 162 is attached. This tie rod 150 is a nylon, fiberglass or lexan that allows the tie rod 150 to hold the first end plate 140 and the second end plate 162 fixedly together. It may be made of a strong-dielectric material such as.

Current flows through the terminal in the first end plate 140 causing the switch to generate a decomposition spark current. This decomposition spark current flows from the inner electrode 102 to the outer electrode 120 through the gap 310 formed by the inner electrode 102 overlapping the outer electrode 120. This decomposition spark current is typically 1,000 to 500,000 amps. The electrodes overlap so that a gap 310 is formed between the overlapping electrode surfaces. This gap 310 provides a path for the current to flow and may include air or other gas dielectrics such as sulfur hexafluoride (SF ₆ ), carbon dioxide (CO ₂ ), and the like.

An insulating barrier 130 made of a rigid insulating material provides a pressure vessel and an electrode support for the spark switch and maintains electrical separation of the electrodes. The insulating barrier 130 may be hollow and may extend the length of any portion of the electrodes 102, 120. The composition of the insulation barrier 130 may be plastic, ceramic, or any other material having properties that resist flames and resist heat. Good materials include glass reinforced aliphatic resins that are strong and less prone to sooting.

The external electrode 120 is made of an electrically conductive material such as bronze, tungsten copper alloy or high strength carbon. Suitable materials for the electrodes are those that erode uniformly and smoothly. This external electrode 120 has a terminal end portion opposite the second end plate 162. The inner wall of the outer electrode 170 forms a longitudinal cavity of a size sufficient to house the inner electrode 102 in a mating manner.

The inner electrode 102 is made of an electrically conductive material similar to the outer electrode 120 and is inserted into the terminal end portion of the outer electrode 120 as shown in FIGS. 6 and 7. The inner electrode 102 is fixed at one end to the first portion of the switch 140 and has a terminal end portion opposite the fixed end. The inner electrode 102 has an outer wall 172.

The inner wall of the outer electrode 170 and the outer wall of the inner electrode 172 provide a radial gap region that provides a channel for decomposition spark current between the inner electrode 102 and the outer electrode 120.

This radial gap region 310 may comprise air or any other compound that provides a medium for the decomposition spark current to flow between the inner and outer electrodes 102, 120. This radial gap 310 may be between about 0.001 inch and 1 inch (0.003-2.54 cm), preferably about 0.25 inch (0.635 cm). This gap depends on the voltage present in the switch.

A formula describing the general behavior of a spark gap switch as a function of gas type, gap length and gas density is given by Equation 1 below.

Where V is the switch breakdown voltage, ρ is the gas density, d is the gap length, and k and β are constants depending on the type of gas. For example, when p is the density of the atmosphere and d is in millimeters, for air, k is 2.45 and β is 2.1. For another frequently used gas, sulfur hexafluoride (SF ₆ ), k is 6.8 and β is 7.5. A graph showing the above formulas and their deviations from these formulas is given in Power ″ Insulations Applied to Circuit Breakers ″, chapter 12, Power Circuit Breaker Theory and Design, edited by D.Legg, CH Flurscheim. .

A terminal gap 410 is formed between the terminal end portion of the outer electrode 120 and the terminal end portion of the inner electrode 102. The terminal gap 410 needs to be large enough to prevent a short circuit situation in the switch when debris accumulates. This terminal gap may range from 1 to 15 times the size of the gap 310.

As shown in FIGS. 6 and 7, the second terminal gap 420 is formed at the switch end opposite to the first terminal gap 410. The second terminal gap 420 also prevents a short circuit in the switch. It has a size in a range similar to that of the first terminal gap 410.

The terminal gaps 410 and 420 tend to collect debris that accumulates during switching. A fluid, either a gas or a liquid, or a combination of the two may exit the switch through the inlet port 414 through the outlet port 415 to prevent accumulated debris from reducing the operating life of the switch 101. . Suction port 414 has a cover 416 that can be closed when no fluid is injected into switch 101. Discharge port 415 also has a cover 416 that closes discharging port 415 when no fluid is injected into switch 101.

An advantage of the spark switch design of the present invention is that the cleanliness of the insulation barrier 130 is improved. Positioning the outer electrode 120 on the inner electrode 102 serves to shield the insulation barrier 130 material from debris produced by the switching action. During switching, the decomposition spark current flows from the inner electrode 102 to the outer electrode 120 to produce byproducts and ultraviolet light in the molten and solid state that tend to contaminate and degrade the insulating barrier 130 material. The design of the present invention is that the external electrode 120 forms a sleeve-type barrier so that the insulation barrier 130 is not exposed to debris and by-products due to arc current generated when a switching action occurs, and thus the service life of the insulation barrier 130 is increased. To extend.

7 shows a spark switch 301 with elongated cylindrical electrodes 102, 120. The operating life of the switch 301 can be increased by further increasing the surface area of the electrodes 102, 120. This is done in one embodiment to increase the length of the inner and outer electrodes 102, 120 along its longitudinal axis. As the length of both inner electrode 102 and outer electrode 120 is increased, this increases the exposed surface area of the electrode. The second end plate 162 of this elongated embodiment has a cavity that allows the overlapping electrodes 102, 120 to extend beyond the second end plate 162.

As shown in FIG. 7, the inner electrode 102 may be a hollow cylinder having an electrode plate on the outside of the cylinder.

The elongated electrode design depicted in FIG. 7 has the additional advantage that a larger surface area further dissipates the heat generated during the decomposition spark current flow.

8 shows a cross-sectional view of a spark gap switch. This gap 310 is disposed between the overlapping electrodes 102, 120.

9 shows that there may be several overlapping electrodes. The electrode surface 105 is connected to the outer electrode 120 and overlaps within the inner electrode 102. The electrode 105 and the inner electrode 102 are spaced apart to form a second radial gap 305. This second radial gap 305 conducts current in the same manner as the gap 310. This setting provides multiple electrode surfaces for switching. These multiple electrodes 102, 105, 120 act to further increase the exposed electrode surface area to increase the operating life of the switch 101.

10 illustrates a coaxial embodiment of spark switch 601. This embodiment does not require an end plate, but rather has a connector 615 connected to a power source (not shown) and a connector 616 connected to a load (not shown). In addition, a conductive outer shield 635 surrounds the inner electrode 600 and the outer electrode 620. The coaxial embodiment of FIG. 10 has a screw-like means 655 for holding the insulating material 630. There is a pressurized region 622 filled with gas. The gap 609 is formed between the inner electrode 600 and the outer electrode 620. Insulating retainer end plugs 654 and 656 support the electrodes 600 and 620. These retainer end plugs 654 and 656 may be made of polycarbonate, for example.

FIG. 11 shows a coaxial spark switch 701 with electrodes 700, 720 included inside a conductive tube 770 providing a return path for current returning back to the voltage source 780 past the load 775. do. The external electrode 720 is connected to the voltage source 780 via the coaxial connector 719. The internal electrode 720 is connected to the load 775 via the coaxial connector 718. The coaxial connectors 718, 719 include inner conductor materials 717, 714, respectively. The internal conductive material 717 is connected to the switch connector 716 and the internal conductive material 714 is connected to the switch connector 715. This embodiment allows the electromagnetic field generated by the switch to be fully contained within the conductive tube 770. This reduction reduces switch inductance, lowers system inductance and reduces electromagnetic noise generated by faster switching performance.

The operating environment of these switches defines good construction materials. For example, a high density electrically conductive material electrode configuration, such as a copper tungsten matrix (10-30% copper, excess of tungsten), increases operating life, but also consists of smaller density materials. Increase the mass of these switches compared to its mass. Higher densities erode more slowly.

In embodiments requiring very high pulse repetition rates, such as 1000 Hz, this adds additional thermal stress to the insulation barrier, and ceramic insulation may be better than plastic insulation. In addition, the use of rigid materials as insulation barriers may be good in some operating environments.

Although the inner electrode and outer electrode are illustrated as cylindrical, the electrode is not limited to a round shape and may include any shape of electrode suitable to surround so that a gap through which decomposition spark currents can pass between electrode moons is formed.

It is evident that the present invention provides a pulsed corona discharge device that fully satisfies the objects, means and advantages described above. Although the present invention has been described in connection with this embodiment, it will be apparent to those skilled in the art that many variations, modifications and variations are possible in light of the above description. Accordingly, all such modifications, changes and variations are included that fall within the spirit and broad scope of the appended claims.

Claims (41)

In the reactor for treating contaminated fluid having a power supply section 12 and a reactor section 10, The power supply section 12 may provide an intermittent high voltage pulse to the electrically conductive header plate 14 of the reactor section 12, The reactor section 10 includes the electrically conductive header plate 14, and also A plurality of first electrodes 16 electrically interconnected to the header plate 14, A plurality of second electrodes 22 concentrically disposed around one of the first electrodes 16 to define a plurality of reactor chambers containing the contaminated fluid 40, An electrically conductive reactor plate 20 electrically interconnected with the plurality of second electrodes 22 and electrically insulated from both the header plate 14 and the plurality of first electrodes 16; A manifold 36 which surrounds the header plate 14 and the reactor plate 20 to form a gas receiving cavity 34; An inlet 42 for delivering the contaminated fluid 40 to the gas receiving cavity 34, And an outlet (58) for recovering the adjusted fluid (54) from the downstream ends of the plurality of second electrodes (22). The method of claim 1, Each of the plurality of first electrodes 16 is applied with a tension applied by a combination of the header plate 14 and the electrically conductive tension plate 64, and the plurality of second electrodes 22 are connected to the header plate ( 14) and the tension plate (64). The method of claim 2, Wherein the plurality of first electrodes (16) is a wire having a diameter of about 0.001 inches to about 0.1 inches (0.003-0.254 cm). The method of claim 3, wherein Wherein the plurality of second electrodes (22) is tubular and has an inner diameter of about 0.5 inches to about 3 inches (1.27-7.62 cm). The method of claim 4, wherein Wherein the intermittent pulse is a voltage between about 10 kV and about 200 kV. The method of claim 5, Reactor, characterized in that the electrical contact between the header plate (14) and the reactor plate (20) is by a detachable contact. The method of claim 6, Reactor, characterized in that the electrical contact between the header plate (14) and the reactor plate (20) is by a compression spring (76). The method of claim 6, Reactor, characterized in that a dielectric is disposed between the header plate (14) and the reactor plate (20) and bonded to both sides. The method of claim 8, Wherein the dielectric is a polymer having a thickness of about 0.25 inches to about 2 inches (0.635-5.08 cm). The method of claim 8, The power supply system 12, A connection from the AC power supply 78 to the high voltage power supply unit 80 for converting the AC current into a DC voltage exceeding 10 kV; A control unit 79 for intermittently conducting the alternating current to the high voltage power supply unit 80; A feedback loop 99 between the high voltage power supply unit 80 and the control unit 79 for synchronizing the high voltage power supply unit 80 with the high speed switch 88; An insulation resistor 86 connected between the high voltage power supply unit 80 and the high speed switch 88; A capacitor 90 connected between the insulation resistor 86 and the fast switch 88, The high voltage power supply unit 80 is turned off when the high speed switch 88 discharges, The high speed switch 88 electrically interconnects the high voltage power supply unit 80 and the header plate 14 when discharged and at other times electrically connects the high voltage power supply unit 80 from the header plate 14. Reactor, characterized in that the insulating. The method of claim 10, A feedback loop 161 between the control unit 79 and the sensor 58 is applied to the regulated fluid 54 to determine the level of harmful compound in the regulated fluid 54. Reactor. The method of claim 11, The feedback loop 161 is in communication with a restrictor 160 to regulate the flow rate of the regulated flow 54 and thus adjusts the interdental processing of the contaminated flow 54. Reactor characterized in that. The method of claim 11, And the feedback loop (161) is in communication with the control unit (79) to regulate the power provided by the intermittent high voltage pulses. The method of claim 12, And the feedback loop (161) is in communication with the control unit (79) to regulate the power provided by the intermittent high voltage pulses. A connection from the alternating current 78 supply device to the high voltage power supply unit 80 for converting the alternating current into a direct current voltage exceeding 10 kV; A control unit 79 for intermittently conducting the alternating current to the high voltage power supply unit 80; The high voltage power supply unit 80 is turned off when the high speed switch 88 discharges by synchronizing the high voltage power supply unit 80 with the high speed switch 88 so that the feedback loop 99 and the control unit 79 are turned off. A feedback loop 99 between the high voltage power supply unit 80 and the control unit 79, indicating a discharge position; An insulation resistor 86 connected between the high voltage power supply unit 80 and the high speed switch 88; A capacitor 90 connected between the insulation resistor 86 and the fast switch 88, The high speed switch 88 electrically interconnects the high voltage power supply unit 80 and the header plate 14 when discharging, and at other times, the high voltage power supply unit 80 electrically connects the high voltage power supply unit 80 from the header plate 14. Power supply system, characterized in that to insulate with. The method according to claim 10 or 15, The high speed switch (88) is a spark gap switch. The method of claim 16, And the resistor (86) has a resistance sufficient to electrically insulate the high voltage power supply unit (80), which is a transformer, from the spark gap switch (88). The method of claim 16, And the resistor (86) has a resistance in excess of about 20 kohms. The method of claim 16, And the capacitor (90) emits a charge of energy in excess of about 0.05J. The method of claim 19, The spark gap switch 88 includes a first electrode 92 electrically connected to the capacitor 90, a second electrode 96 electrically connected to the power supply electrode 72, and between the electrodes. And a gap (94) in which the gap (94) is filled with gas. The method of claim 20, And the gas is hydrogen. The method of claim 21, The fast switch (88) is characterized in that it provides a pulse interval of about 100 microseconds to about 1 second. The first connector 115, The second connector 116, Has an internal electrode 102 and an external electrode 120 disposed between the first connector 115 and the second connector 116, The internal electrode 102 Proximal end, A terminal end opposite the terminal end Including an outer wall 172, The external electrode 120 is Distal end, A terminal end opposite the terminal end, The outer electrode 120 defines a cavity for receiving at least a portion of the inner electrode 102, and the outer wall 172 of the inner electrode 102 and the cavity of the outer electrode 120 form a radial gap 310. and, The switch (101), characterized in that the first terminal gap (410) is between the terminal end portion of the outer electrode (120) and the terminal end (102) of the inner electrode (102). The method of claim 23, Switch, characterized in that the insulating material 130 is disposed around the external electrode (120). The method of claim 24, The insulating material 130 is a switch, characterized in that the ceramic. The method of claim 24, The external electrode (120) surrounds the internal electrode (102) to shield the outside of the switch. The method of claim 23, And a surface of the third electrode (105) superimposed within the inner electrode (102) forms a second radial gap (305) between the third electrode (105) and the inner electrode (102). The method of claim 23, And the distance of the radial gap is based on the voltage applied between the inner electrode and the outer electrode. The method of claim 28, The radial gap 310 can be sized from about 0.001 inches to about 1.0 inches (0.003-2.54 cm). The method of claim 29, And the second terminal gap (420) is opposite the first terminal gap (410). The method of claim 30, And the terminal gap (410) ranges in size from about 1 to 15 times the size of the terminal gap (310). The method of claim 23, A first end plate 140 between the first connector 115 and the electrodes 102 and 120, And a second end plate (162) between the electrodes (102, 120) and the second connector (116). The method of claim 32, At least one end plate (140, 162) has a suction port (414). The method of claim 32, At least one end plate (140, 162) has a discharge port (415). The method of claim 32, The switch characterized in that the second end plate (162) has a radial opening for receiving a portion of the external electrode (120). 36. The method of claim 35 wherein Wherein the inner electrode and the outer electrode are substantially cylindrical in shape. Providing an external electrode 120 having a terminal end, Providing an internal electrode 102 having a terminal end, A radial gap 310 is formed between the inner electrode 102 and the outer electrode 120 for a crack breakdown current and between the terminal end of the outer electrode 120 and the terminal end of the inner electrode 102. And superimposing the inner electrode (102) inside the cavity of the outer electrode (120) to form a terminal gap (410). The method of claim 37, The method of increasing the life of the spark switch operation, characterized in that it further comprises the step of arranging the insulating material (130) in the shape of a sleeve around the external electrode (120). The method of claim 2, And overlapping the third electrode (105) inside the inner electrode (102) to form a second radial gap (305). Internal electrode 700, An external electrode having a cavity for receiving at least one portion of the internal electrode 700 in a paired manner such that a radial gap 609 is formed between the external electrode 720 and the internal electrode 700 for a decomposition spark current ( 720), A conductive tube 770 surrounding the inner electrode 700 and the outer electrode 720, A first coaxial connector 718 for connecting one of the electrodes 700 to an electrical load 775, And a second coaxial connector (719) for connecting one of the other electrodes (700) to a power source (780). The method of claim 40, A first insulating material 654 disposed between a portion of the inner electrode 600 between the inner electrode 600 and the conductive tube 770 such that the inner electrode 600 is insulated from the conductive tube 770; Disposed between the outer electrode 620 and the conductive tube 770 around a portion of the outer electrode 620 such that the outer electrode 620 further comprises a first insulating material 654 that is insulated from the conductive tube 770. A coaxial switch 601.